diff options
| -rw-r--r-- | guix/build/syscalls.scm | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/guix/build/syscalls.scm b/guix/build/syscalls.scm index d75c11ada7..6f2a061f35 100644 --- a/guix/build/syscalls.scm +++ b/guix/build/syscalls.scm @@ -73,6 +73,7 @@ file-system-mount-flags statfs free-disk-space + device-in-use? processes mkdtemp! @@ -684,6 +685,27 @@ mounted at FILE." (define AT_NO_AUTOMOUNT #x800) (define AT_EMPTY_PATH #x1000) +(define-syntax BLKRRPART ;<sys/mount.h> + (identifier-syntax #x125F)) + +(define* (device-in-use? device) + "Return #t if the block DEVICE is in use, #f otherwise. This is inspired +from fdisk_device_is_used function of util-linux. This is particulary useful +for devices that do not appear in /proc/self/mounts like overlayfs lowerdir +backend device." + (let*-values (((port) (open-file device "rb")) + ((ret err) (%ioctl (fileno port) BLKRRPART %null-pointer))) + (close-port port) + (cond + ((= ret 0) + #f) + ((= err EBUSY) + #t) + (else + (throw 'system-error "ioctl" "~A" + (list (strerror err)) + (list err)))))) + ;;; ;;; Containers. |